/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.catalina;

/**
 * A <b>Cluster</b> works as a Cluster client/server for the local host
 * Different Cluster implementations can be used to support different ways to
 * communicate within the Cluster. A Cluster implementation is responsible for
 * setting up a way to communicate within the Cluster and also supply
 * "ClientApplications" with <code>ClusterSender</code> used when sending
 * information in the Cluster and <code>ClusterInfo</code> used for receiving
 * information in the Cluster.
 * 
 * @author Bip Thelin
 * @author Remy Maucherat
 * @author Filip Hanik
 * @version $Revision: 500684 $, $Date: 2007-01-28 07:27:18 +0800 (星期日, 28 一月
 *          2007) $
 */

public interface Cluster {

	// ------------------------------------------------------------- Properties

	/**
	 * Return descriptive information about this Cluster implementation and the
	 * corresponding version number, in the format
	 * <code>&lt;description&gt;/&lt;version&gt;</code>.
	 */
	public String getInfo();

	/**
	 * Return the name of the cluster that this Server is currently configured
	 * to operate within.
	 * 
	 * @return The name of the cluster associated with this server
	 */
	public String getClusterName();

	/**
	 * Set the name of the cluster to join, if no cluster with this name is
	 * present create one.
	 * 
	 * @param clusterName
	 *            The clustername to join
	 */
	public void setClusterName(String clusterName);

	/**
	 * Set the Container associated with our Cluster
	 * 
	 * @param container
	 *            The Container to use
	 */
	public void setContainer(Container container);

	/**
	 * Get the Container associated with our Cluster
	 * 
	 * @return The Container associated with our Cluster
	 */
	public Container getContainer();

	/**
	 * Set the protocol parameters.
	 * 
	 * @param protocol
	 *            The protocol used by the cluster
	 * @deprecated
	 */
	public void setProtocol(String protocol);

	/**
	 * Get the protocol used by the cluster.
	 * 
	 * @return The protocol
	 * @deprecated
	 */
	public String getProtocol();

	// --------------------------------------------------------- Public Methods

	/**
	 * Create a new manager which will use this cluster to replicate its
	 * sessions.
	 * 
	 * @param name
	 *            Name (key) of the application with which the manager is
	 *            associated
	 */
	public Manager createManager(String name);

	/**
	 * Register a manager with the cluster. If the cluster is not responsible
	 * for creating a manager, then the container will at least notify the
	 * cluster that this mananger is participating in the cluster.
	 * 
	 * @param manager
	 *            Manager
	 */
	public void registerManager(Manager manager);

	/**
	 * Removes a manager from the cluster
	 * 
	 * @param manager
	 *            Manager
	 */
	public void removeManager(Manager manager);

	// --------------------------------------------------------- Cluster Wide
	// Deployments

	/**
	 * Execute a periodic task, such as reloading, etc. This method will be
	 * invoked inside the classloading context of this container. Unexpected
	 * throwables will be caught and logged.
	 */
	public void backgroundProcess();
}
